diff options
| -rw-r--r-- | doc/cd-text-format.texi | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/doc/cd-text-format.texi b/doc/cd-text-format.texi index c37d4024..67526754 100644 --- a/doc/cd-text-format.texi +++ b/doc/cd-text-format.texi @@ -102,7 +102,7 @@ Additional notes regarding Pack Types: @item Pack Types @kbd{0x8a} to @kbd{0x8c} although not specified are reserved for potential future use. @item Pack Types @kbd{0x86}, @kbd{0x87}, @kbd{0x88}, @kbd{0x89}, @kbd{0x8d} (Disc Identification, Genre Identification, Table of Contents, Second Table of Contents and Closed Information respectively) apply to the whole -disc, and can not be attached to individual tracks. +disc, and cannot be attached to individual tracks. @item Pack Types @kbd{0x80}, @kbd{0x81}, @kbd{0x82}, @kbd{0x83}, @kbd{0x84}, @kbd{0x85}, and @kbd{0x8e} (Performers, Songwriters, Composers, Arrangers, and Message Area respectively) have to be attributed to @@ -113,9 +113,9 @@ each track if they are present for the whole disc. The total size of a block's attribute set is restricted by the fact that it has to be stored in at most 253 records with 12 bytes of payload. These records are called @emph{Text Packs} described in the -next section. A shortcut for repeated identical track texts is -provided, so that a text that is identical to the one of the previous -track occupies only 2 or 4 bytes. +next section. Since information such as the Disc and Genre +Identification is often the same across mutiple tracks, a compact way +to repeat identical information is provided. @node Pack Contents @section Pack Contents @@ -141,11 +141,12 @@ The first byte of each pack contains the pack type. See The second byte often gives the track number of the pack. However, a zero track value indicates that the information pertains to the whole -album. Higher numbers are valid for types @kbd{0x80} to @kbd{0x85}, -and @kbd{0x8e}. In these pack types, there should be one text pack for -the disc and one for each track. With types @kbd{0x88} and -@kbd{0x89}, the second byte is a track number too. With type -@kbd{0x8f}, the second byte counts the record parts from 0 to 2. +album. Higher numbers are valid for track-oriented packs (types +@kbd{0x80} to @kbd{0x85}, and @kbd{0x8e}). In these pack types, there +should be one text pack for the disc and one for each track. With TOC +packs (types @kbd{0x88} and @kbd{0x89}), the second byte is a track +number too. With type @kbd{0x8f}, the second byte counts the record +parts from 0 to 2. The third byte is a sequential counter. @@ -186,9 +187,10 @@ at most 2048 text packs possible. If a text of a track (pack types @kbd{0x80} to @kbd{0x85} and @kbd{0x8e}) repeats identically for the next track, then it may be -represented by a TAB character (ASCII 9) for single byte texts, -resp. two TAB characters for double byte texts. (This should be used -because 256 * 12 bytes is few space for 99 tracks.) +represented by a TAB character (ASCII 9) for single byte texts, and +two TAB characters for double byte texts. This is desirable because +there is a somewhat limited amount of space for CD Text --- 256 * 12 +bytes which may have to accomodate up to 99 tracks. The two binary bytes of pack type @kbd{0x87} are written to the first @kbd{0x87} pack of a block. They may or may not be repeated at the start |